Vargas-Pérez Héctor, Sellings Laurie, Grieder Taryn, Díaz José-Luis
Departamento de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Querétaro, Mexico.
Neurosci Lett. 2009 Jul 3;457(3):137-40. doi: 10.1016/j.neulet.2009.03.098. Epub 2009 Apr 5.
Dominance hierarchies within social groups determine resource distribution. Resources, such as food and access to mating partners, can act as reinforcers. The present study examined the effect of social rank on access to wheel running-a reinforcing behavior performed by laboratory animals. Mice were identified as dominant or subordinate and given access to a running wheel access under solitary or social conditions. In the solitary condition, subordinate and dominant mice spent equal amounts of time on the running wheel. In the social condition, when one wheel was present, subordinate mice spent less time on the wheel than did dominant mice. Conversely, when two wheels were present, subordinates spent more time on the wheel than did dominant mice. When mice were given 24h access to one running wheel in the social condition, dominant mice ran more than subordinates during the dark cycle. Subordinate mice did not compensate for the lack of running wheel access by schedule shifting. These results suggest that social rank influences access to reinforcers by behavioral interference rather than by social inhibition.
社会群体中的等级制度决定资源分配。食物和交配机会等资源可以起到强化物的作用。本研究考察了社会等级对使用跑步轮的影响——这是实验室动物表现出的一种强化行为。将小鼠分为优势鼠和从属鼠，并在单独或群居条件下让它们使用跑步轮。在单独条件下，从属鼠和优势鼠在跑步轮上花费的时间相等。在群居条件下，当只有一个跑步轮时，从属鼠在跑步轮上花费的时间比优势鼠少。相反，当有两个跑步轮时，从属鼠在跑步轮上花费的时间比优势鼠多。在群居条件下，当给小鼠24小时使用一个跑步轮的机会时，优势鼠在黑暗周期中的跑步量比从属鼠多。从属鼠不会通过改变时间表来弥补无法使用跑步轮的情况。这些结果表明，社会等级通过行为干扰而非社会抑制来影响对强化物的获取。
